As shown in FIG. 5A, there is a power supply device 100, as a conventional power supply device equipped with a protective function for protecting a load from an overcurrent, provided with a fuse F along an output end of a constant-voltage source E with which loads L1-L4 are connected in parallel through switches S1-S4, respectively.
In this power supply device 100, there is an issue that power feeding to all the loads L1-L4 is shut off when the fuse F is melted by an overcurrent, because the loads L1-L4 are protected from an overcurrent with the fuse F connected along the output end of the constant-voltage source E.
Therefore, in order to protect each load of branch circuits from an overcurrent, a conventional power supply device 101 is provided with a multipoint connector 102 connected with a plurality of load circuits as shown in FIG. 5B (e.g., Patent Documents 1-4). In this power supply device 101, a direct-current power from a constant-voltage source E is supplied to loads L1-L3 connected to the multipoint connector 102 via built-in circuit protectors CP1-CP3. When an overcurrent flows by occurrence of short-circuit or the like at any of the loads L1-L3, the power supply device 101 shuts off, through a break operation by a corresponding one of the circuit protectors CP1-CP3, only power feeding to the branch circuit through which the overcurrent flows. Accordingly, power feeding to the remaining load circuits can be continued.